3 0 0 0 OA 飲料中の気泡が壁面近傍に形成する数密度分布について
- 著者
- 岩坪 史弥 渡村 友昭 杉山 和靖 山本 研一朗 四元 祐子 塩野 貴史
- 出版者
- 日本混相流学会
- 雑誌
- 混相流 (ISSN:09142843)
- 巻号頁・発行日
- vol.32, no.1, pp.124-131, 2018-03-15 (Released:2018-05-03)
- 参考文献数
- 20
To clarify the spatial structure of number density distribution of bubbles in stout beer poured into a container, we investigated local time development of the void fraction and velocity of bubbles. The propagation velocity of the texture, i.e. the number density distribution, appearing near the inclined wall of the container is measured by the images analysis. We measured the local void fraction using brightness of images while the velocity of bubbles by means of Particle Tracking Velocimetry. As the result of measurements, we found the local void fraction and the bubbles advection velocity increase and decrease repeatedly with a time delay. We conclude the pattern of the number density distribution of bubbles is composed of fluid blobs which contain less bubbles; extruding and suction flows respectively toward and from the interior of the container form respectively in front and back of the blobs.
2 0 0 0 OA 天然吸着剤による飲料からのカフェイン除去技術
- 著者
- 塩野 貴史 河合 淳一郎 山本 研一朗
- 出版者
- 公益社団法人 日本食品科学工学会
- 雑誌
- 日本食品科学工学会誌 (ISSN:1341027X)
- 巻号頁・発行日
- vol.65, no.3, pp.99-103, 2018-03-15 (Released:2018-03-20)
- 参考文献数
- 13
In recent years, the demand for beverages with lower caffeine concentrations has been expanding. However, traditional decaffeination technologies for tea and coffee not only remove caffeine, but also reduce the active components responsible for beverage flavor and quality. In this study, we investigated the selectivity and versatility of decaffeination by montmorillonite (MMT) in beverages. MMT adsorbed caffeine from tea and coffee extracts more selectively than activated carbon (AC). Optimization of the contact conditions enabled stable decaffeination and prevented elution of Fe ions from MMT, which causes discoloration of tea beverages. MMT exhibited similar caffeine adsorption properties with various types of tea extracts and coffee extracts. In addition, ion-exchanged MMTs, which also removed caffeine, improved the appearance quality of decaffeinated beverages. Overall, our findings suggest that MMT is a useful adsorbent for producing high-quality decaffeinated beverages. Specifically, decaffeinated tea beverages treated with MMT have been commercially available since 2014 from Kirin Beverage Company Ltd.